thanos update to 15.4.3-bb.0

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/thanos/-/blob/15.4.3-bb.0/CHANGELOG.md

Package MR

big-bang/product/packages/thanos!63 (merged)

For Issue

Closes big-bang/product/packages/thanos#41 (closed)

Upgrade Notices